Aircraft with freewheeling engine

ABSTRACT

An aircraft may have a fuselage, a left wing extending from the fuselage, a right wing extending from the fuselage, a tail section extending from a rear portion of the fuselage, and a first engine and a second engine operably connected by a common driveshaft, wherein the first and second engines are configured for freewheeling such that if one of the first and second engines loses power the other of the first and second engines continues to power the aircraft.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.13/012,763 filed Jan. 24, 2011, which is a continuation-in-part of U.S.patent application Ser. No. 11/581,321 filed Oct. 16, 2006, which claimspriority to U.S. Provisional Patent Application No. 60/727,798 filedOct. 18, 2005, the disclosures of each of which are incorporated hereinby reference.

FIELD

This invention relates generally to Vertical Take-Off and Landing (VTOL)aircraft and more specifically to a compact VTOL aircraft with a fixedwing which can be utilized as a Personal Air Vehicle (PAV) or anUnmanned Aerial Vehicle (UAV).

BACKGROUND

Inventors have long contemplated and attempted to design vehicles whichwould serve as a combination car/airplane. That creation could be drivenas a car to an airport where it would be converted with wings and thenflown like an airplane. Upon landing, the aircraft would be convertedback to a car and then driven on a roadway to a destination. The Aerocar(1959) by Molt Taylor and the recent “Transition” flying car byMassachusetts Institute of Technology graduate student Carl Dietrich andthe MIT team show a continuation of that dream. However, that dream hasnot been fully realized, and a need still remains for an aircraft thatmay operate without being constrained to airports or roadways.

SUMMARY

The present disclosure is directed to an aircraft that contemplates noneed for driving a car through traffic to and from airports. Thecapabilities and properties of this particular aircraft make it compactand versatile enough so as to enable a pilot to fly this aircraft from“door to door” without the requirement of an airport or highways. Forexample, a person could lift off as with a helicopter from a space suchas a driveway, back yard, parking garage, rooftop, helipad, or airportand then fly rather than drive to all the day's various appointments.Some embodiments of the present invention provide a versatile VTOLaircraft that is not only lightweight and powerful enough to take offand land vertically, but is also economical and powerful enough to takeoff, land and fly at a fast rate of speed, like an airplane. Therefore,it serves as a personal air vehicle (PAV) with a multitude of uses andconfigurations. The ability to transition from vertical flight toforward flight and back again provides unlimited possibilities becauseit combines the flexibility and best attributes of both types ofaircraft.

In some embodiments, the current invention is able to achieve its powerfrom the placement and production of two (2) Axial Vector/Dyna-Cam typeengines mounted sideways with respect to the fuselage of the aircraft(that is, the axis of rotation of the driveshaft of each engine may beoriented transverse to the longitudinal axis of the fuselage). Theseengines are lightweight and produce greater horsepower and three (3)times more torque per horsepower than conventional engines. Each enginemay have a double-ended driveshaft which provides direct drive to theducted fans/nacelles which are located outside of the fuselage. Each endof each double-ended driveshaft may turn one ducted fan, so two engineswill power two (2) pairs of ducted fans for a total of four ducted fans.

Forward Engine

In some embodiments, a first engine may be placed in the front sectionof the aircraft fuselage, and the driveshafts from the ends of the firstengine may run through a front canard wing on the aircraft to a frontpair of ducted fans located at the ends of the canard wing. These frontducted fans may be mounted far enough out from the fuselage to preventpropeller wash in the rear ducted fans.

Rear Engine

In some embodiments, a second engine may be mounted behind the passengercabin and toward the rear of the fuselage. This engine may power an ofpair of ducted fans which are attached to the fuselage, so thedriveshaft for this engine may connect directly through a transfer caseto differentials in the ducted fans. The rear engine may be slightlyelevated above the center line of the side of the fuselage.

In-Line Configuration

The two sideways mounted engines may be placed in-line in the fuselageso the passenger cabin and the rear engine receive less wind resistance,thus reducing drag on the airplane and increasing fuel efficiency. Asearly as 1937, Dr. Claude Dornier used the in-line configuration in hisGerman built Dornier DO335. By the 1960s, the Cessna Skymaster 336 wasusing in-line engines, and presently the Adams A500 designed by BurtRutan is utilizing the configuration. Since the engines are locatedinside the fuselage rather than outside in the ducted fans or at the endof a main wing, as on the Bell Boeing V-22 Osprey, a better in-linecenter of gravity is established thereby resulting in quicker response,better balance and increased stability in flight and/or in hover.

Ducted Fans

In some embodiments, the aircraft may have a fixed wing and fouraerodynamically designed tilt ducted fans. As early as the 1960s, theBell X-22A was one of the first aircraft to fly using tilt ducted fans.More recently, Moller's “Skycar” (U.S. Pat. No. 5,115,996) is a vehiclewhich includes ducted fans with directional vanes and two engines ineach duct for a total of eight engines. Unlike the X-22 with its fourengines and Moeller's car with its eight engines, some embodiments ofthis invention use only two sideways placed engines in the fuselage withdirect drive from the driveshafts into differentials in the ducted fansto power four ducted fans, with no intervening transmission between therotor of each engine and the driveshaft or between the driveshaft andthe differentials. The elimination of a transmission in such a directdrive embodiment saves weight and increases efficiency and performance.

The fact that only a differential rather than a motor is located in theducted fans of some embodiments of this invention creates a largervolume of airflow through the ducted fans. Eliminating the weight of themotors or engines outboard of the fuselage also reduces the weight onthe side of the fuselage and/or the wing tips, thereby using lesshorsepower and torque and in turn making the aircraft more responsiveand stable.

Most ducted fans have a problem when reaching higher speeds because of atendency to push air out in front of the duct. In some embodiments ofthe current invention, the aerodynamic shape of the front of the ductedfans is such that the bottom of each duct protrudes forward and the topof each duct slopes down to the bottom. This lifting air intake ductdesign creates low pressure in the bottom front of the duct which helpseliminate the need for more wing area and in turn reduces the weight ofthe aircraft. Willard Custer illustrated this lift principle with hisChannelwing aircraft in the late 1930s. This technology is beingresearched even today at the Georgia Institute of Technology.

Another result of extending the bottom of the ducts is a reduction ofthe noise created by the turning blades. In a UAV stealth design, thiswill also help cover the radar signature from the turning blades.

In some embodiments, ducted fans permit the aircraft to take off andland in either conventional or VTOL mode. Since the fan blades may beencased in ducts, the ducts can be rotated to align horizontally withthe fuselage, and the aircraft may take off and land conventionally. Insome embodiments, such ducted fans may provide greater flexibility interms of sizing, thrust, and ground clearance than if unductedpropellers are used. In some embodiments, a double row ofcounter-rotating fan blades in the ducted fans may provide sufficientthrust so that the duct diameter may be small enough for sufficientground clearance. In some embodiments, conventional take-off and landingmay also be provided because the double row of counter-rotating bladesin the ducted fans allow the ducted fans to be small enough to clear theground when oriented horizontally. In some embodiments, VTOL is possiblebecause the ducted fans may rotate to a vertical orientation and providesufficient thrust for take-off and landing.

Lifting Body Airframe

In some embodiments, the aircraft body itself may be an aerodynamicallydesigned lifting body. As far back as the 1920s, Burnelli Aircraft wasbuilding a lifting body airframe (U.S. Pat. No. 1,758,498). Today, theSpace Shuttle still utilizes that technology. With the engines mountedsideways with respect to the fuselage, this design lends itself to alifting body application.

Emergency Parachute

Some embodiments of the current invention include a power boostedemergency parachute assembly which can be used in hover or flightconditions, should the aircraft lose one or more of its engines, thusallowing the pilot to continue to maneuver the aircraft to a safelanding.

Fly-by-Wire Control System

Some embodiments of the current invention incorporate a computercontrolled fly-by-wire system which calculates gyroscopic stability andsends information to one or more ducted fans or propeller blades toadjust them to the correct pitch for controlled flight.

Fixed Wing with Removable Sections

In some embodiments, the aircraft may have a fixed level, dihedral, oranhedral wing to provide for forward flight in airplane mode. Sectionsof the aircraft wings may be bolted on or removed to create various winglengths for different applications, such as for short distances as in acity setting or long distances for long range travel and for easytransporting of the aircraft, as on a trailer or truck or in a shippingcontainer. For example, extensions on the main wing may enable anaircraft to fly at high altitude and/or to loiter for long periods oftime.

By combining the attributes of a fixed wing airplane and a helicopter toa lightweight and compact aircraft, a personal air vehicle may become anew mode of transportation. The embodiments set forth herein are merelyexamples of various configurations of the aircraft, and many new modelscan result from this invention. Different embodiments of this aircraftcould range from a variety and number of passenger seating arrangementsto a model with no passengers; i.e., a UAV. In other applications, theaircraft may serve as a personal air vehicle, an air taxi, anobservation aircraft, an emergency rescue vehicle, a military vehicle ora UAV, or for other purposes.

Some embodiments may be constructed of lightweight material and theairframe may be designed as a lifting body, which helps reduce theweight and the square footage area of the wings.

Some embodiments may have the vertical take-off, landing and flightcapabilities of a helicopter and the conventional take-off, landing andflight capabilities of an airplane. Some embodiments may transition backand forth between VTOL and forward flight. If the aircraft is in hoverposition, air deflectors (which may be mounted on the rear of eachducted fan) may enable the aircraft to move sideways and to counterrotate, and the tilted ducted fans may enable it to move forward andbackward safely in tight spaces. Since some embodiments of the aircraftmay use significant power to accommodate its VTOL capabilities, theaircraft may also be designed to take advantage of this power andtransform it into maximum airspeed in forward flight.

All these capabilities make this a truly unique aircraft, capable of amultitude of uses. Some embodiments of the current invention can liftoff and set down like a helicopter, but can also utilize the speed of anairplane to provide quick “door to door” service for convenience and forthe saving of time and fuel.

Since some embodiments of the aircraft can take off like an airplane, itmay be capable of handling more weight—such as that of passengers, fueland freight—on takeoff and then traveling a longer distance. In someembodiments, the aircraft may land in a conventional aircraft mode on arunway, if desired, or the aircraft may land vertically in a smallerspace or without a runway. In some embodiments, the compact nature ofthe aircraft, combined with the use of ducted fans, may provide a largespectrum of landing locations for it as a VTOL vehicle.

Although some embodiments of the aircraft may not be as fast as the newlight jets currently being developed and soon to be offered for air taxiservice, the aircraft nonetheless saves overall time because it can takeoff and land in locations other than a landing strip. Time commuting toand from an airport can be significant, and some embodiments of thisaircraft may provide a means to bypass airports by leaving from andreturning to a nearby convenient location.

In some embodiments, one advantage of the fixed wing aircraft is theability to throttle back the engines and use lift from the wing to helpthe engines conserve fuel while flying. In some dual engine embodiments,either engine may be shut off, and the aircraft can cruise on one enginefor improved fuel economy. For example, Burt Rutan's Voyager took offusing both engines, then shut down one engine and flew around theworld—using one engine—without refueling. Additionally, the wing may bedihedral, which may improve the stability of the aircraft.

In some dual engine embodiments, if one engine is lost, the aircraft canfly on either of its engines and continue to an airport to landconventionally. If both engines are lost while in flight, the aircraft'sglide slope is excellent. The pilot can glide the aircraft to a landingsite or use a guidable emergency parachute to float to a safe location.

In some embodiments, another advantage derives from the fact that theengines are not in the ducts but are instead mounted in the fuselage,providing an in-line center of gravity for better stability andincreased response (as opposed to having the weight of the engines onthe wingtips). Additionally, the front engine may break the air for boththe cabin and the rear engine, thus creating a very aerodynamic liftingbody aircraft.

In some embodiments, the elevation of the rear engine may allow for airintake scoops to be mounted on the front of each side of the engine,thereby providing for air cooling of the rear engine while stillmaintaining the aircraft's aerodynamic design. In conventional airplanemode, this elevation may also improve the flare of the aircraft uponlanding and derotation and may allow the rear landing gears to hit therunway first. It also may improve take-off and rotation because thefront landing gear of the aircraft may lift off first.

In some embodiments, another advantage in landing an aircraft asdescribed herein is that, in the case of an engine being lost, the twoducted fans attached to that engine may stop also. Consequently, thecritical engine problem which causes yaw and then roll, usuallyexperienced when a twin engine aircraft loses an engine, may beeliminated. Additionally, if an engine is lost, some embodiments of theaircraft are capable of auto feathering the fan blades of the two ductedfans associated with that engine, thereby reducing drag through theduct.

In some embodiments, the sideways placement of the engines may providethe ability to power two ducted fans with one engine having adouble-ended driveshaft. In such embodiments, the cost of constructionand operation of the aircraft may be less, for example, because only twoengines may be used to power four ducted fans.

In some embodiments, one or more driveshafts of the rear engine may beshortened going into the associated rear ducted fans because the ductedfans may be mounted on the side of the fuselage, and one or moredriveshafts of the front engine may be shortened going through a canardwing which may not be as long as a main wing. This configuration notonly may reduce the weight of the one or more driveshafts, but may alsoprovide an enhanced safety factor. Since a driveshaft may enter themiddle of a differential in a ducted fan, the driveshaft may naturallyturn two output shafts of the ducted fan in a counter rotating motion.This reliable yet simple design may also add to the safety of theaircraft.

In some embodiments, the aircraft may use an Axial Vector/Dyna-Cam typeengine which may provide many advantages, including very smoothoperation with little vibration and utilization of a variety of fuelsand high fuel efficiency. The Axial Vector/Dyna-Cam type engine is alightweight, small and compact internal combustion engine with highhorsepower and high torque. A high torque engine may allow a high angleof attack on variable pitch blades, which may provide quick responsewith little variation in the rpm of the engine.

In some embodiments, the ducts of the ducted fans may be aerodynamicallydesigned to create lift thereby reducing the weight of the aircraftbecause of less square footage of wing area than otherwise may berequired. Since no engines are located in the ducts, more area isavailable for airflow through the ducts, thus creating more lift andthrust. In some embodiments, the front pair of ducts may be mounted farenough out on the canard wing to allow the rear ducts to receiveundisturbed air.

In some embodiments, two rows of blades in a ducted fan may turn in acounter rotating motion thereby creating more thrust and reducing theoverall diameter of the duct. This reduced diameter may providesufficient ground clearance for a conventional aircraft take-off andlanding mode as well as VTOL and VSTOL capability.

Tilt ducted fans may provide the ability to get full thrust on lift andforward flight. The aerodynamic shape of the lifting duct may providefor more lift with less weight since a shorter wing may be used.

In some embodiments, the blades in each row of a ducted fan may havevariable pitch. The pitch angle of the blades may be determined andcontrolled by a computer in communication with gyros in a fly-by-wiresystem, thus controlling pitch for stability in a hover mode oradjusting pitch while in forward flight. The blades may have thecapability of self feathering and lining up in an identicalconfiguration behind one another within each duct to help reduce dragand increase air flow through the ducts should an engine be lost or shutdown. This capability may extend the range which can be flown with oneengine.

In some embodiments, the use of ducted fans instead of un-ductedpropellers may provide for safer VTOL. In such embodiments, no exposedpropellers are involved, so the aircraft can land in tight spaces or getclose to people or to stationary objects. For example, it could hovernext to buildings for rescues, land in fields with electrical wires,and/or land in neighborhoods or a regular parking lot. In suchembodiments, since ducts surround the fan blades, the ducted fans may bequieter, enabling the aircraft to take off and land with less noise thanis typically associated with helicopters. This ducted fan design mayalso help reduce or cover the radar signature from the turning blades ina UAV stealth design.

NASA has been researching and developing its “highway in the sky” whichprovides synthetic vision and GPS guidance in aircraft so that pilotscan bypass the large congested airport hubs and land at smallerairports. That technology may be included in some embodiments of thisinvention, which may allow pilots to bypass even the small airports andland at or near their actual destinations, and it may assist in handlingbad weather such as fog.

Some embodiments of this invention may include an emergency parachutesystem that provides for quick deployment and rapid expansion to preventsignificant altitude loss while in hover or for a delayed deploymentwhile in forward flight. Most of the currently used emergencyparachutes—often referred to as whole-airplane recovery parachutesystems—require too much time to fill with air, resulting in asignificant loss of altitude before the parachute can take effect.

The Ballistic Recovery System (BRS) which was invented and patented byBoris Popov (U.S. Pat. No. 4,607,814) was originally created forultralights and experimental aircraft and later retrofitted for largeraircraft. The BRS system is currently utilized by Cirrus Design for itslighter single engine airplanes. However, the emergency parachute systemin the Cirrus aircraft allows a significant loss of altitude before thecanopy is filled with air. Once the Cirrus is descending under theparachute, the pilot has no control of the descent and therefore nocontrol of the landing site. The rocketed parachute system in someembodiments of the present invention may rapidly deploy and expand theparachute and then allow the pilot to steer the parachute to get theaircraft to a preferred landing site.

A sport plane embodiment of this aircraft may have a fuselage having alongitudinal axis, a left wing extending from the fuselage, a right wingextending from the fuselage, a tail section extending from a rearportion of the fuselage, a first ducted fan rotatably mounted to theleft wing, a second ducted fan rotatably mounted to the right wing, andan engine disposed in the fuselage, the engine having a direct-drive,double-ended driveshaft having an axis of rotation oriented transverseto the longitudinal axis of the fuselage, wherein the first ducted fanincludes a first differential operably connected between first andsecond rows of counter rotating fan blades, wherein the second ductedfan includes a second differential operably connected between third andfourth rows of counter rotating fan blades, and wherein one end of thedriveshaft is directly connected to the first differential, and theother end of the driveshaft is directly connected to the seconddifferential.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of a four ducted fan aircraftembodiment of the current invention.

FIG. 2 a is a top schematic cross-sectional view of the aircraft of FIG.1 showing single engines serving the front and rear pairs of ductedfans.

FIG. 2 b is a top schematic cross-sectional view of the aircraft of FIG.1 showing pairs of engines serving the front and rear pairs of ductedfans.

FIG. 3 a is a side schematic cross-sectional view of a ducted fanassembly.

FIG. 3 b is a top schematic cross-sectional view of the ducted fanassembly of FIG. 3 a.

FIG. 3 c is a front view of the ducted fan assembly of FIG. 3 a.

FIG. 4 a is a side view of the aircraft of FIG. 1 in forward flight withrear thrust.

FIG. 4 b is a side view of the aircraft of FIG. 1 in hover with downwardthrust.

FIG. 4 c is a side view of the aircraft of FIG. 1 in braking positionwith reverse thrust.

FIG. 5 is a front perspective view of a Personal Air Vehicle (PAV) or anUnmanned Aerial Vehicle (UAV) embodiment.

FIG. 6 is a front perspective view of a Sport Plane embodiment.

DETAILED DESCRIPTION

As used herein, the following terms should be understood to have theindicated meanings:

When an item is introduced by “a” or “an,” it should be understood tomean one or more of that item.

“Comprises” means includes but is not limited to.

“Comprising” means including but not limited to.

“Having” means including but not limited to.

“Including” means including but not limited to.

VTOL Aircraft with Sideways Mounted Engines

As shown in FIGS. 1 and 2 a, a first embodiment of the current inventionmay have four ducted fans. This embodiment is a VTOL aircraft with two(2) engines—one fore 201 and one aft 202—placed sideways with respect toan elongated lifting body fuselage 100, which may be made of lightweightcomposite materials, aluminum, or other suitable materials. Thisembodiment may have a canard wing 123 on the front, a fixed main wing113 in the middle of the fuselage 100 with winglets 114 attached on eachend of the main wing 113, two vertical stabilizers 120 on the rear, ahorizontal stabilizer 122 across the top of the tail, a pair of ductedfans 106R and 106L fore, and a pair of ducted fans 706R and 706L aft oneach side of the fuselage 100 for a total of four (4) ducted fans. Thecanard wing 123 and the main wing 113 may be level, dihedral, oranhedral, depending on the overall aerodynamic design of the aircraft.In this example, all four ducted fans may have the same design and aresometimes referred to as element 106 in the discussion of thisembodiment. Alternatively, the ducted fans may not all have the samedesign. In other alternative embodiments, un-ducted propellers may beused instead of ducted fans, or a combination of ducted fans andun-ducted propellers may be used.

The engines 201, 202 may be Axial Vector/Dyna-Cam type engines or othersuitable engines. The Axial Vector engine from Axial Vector EngineCorporation is a six piston twelve cylinder radial design with highhorsepower and torque. The engine is small, lightweight and producesthree times the torque per horsepower as compared to some otheravailable engines, thus improving the power-to-weight ratio. It is fuelefficient and can use a variety of fuels. It has fewer parts andproduces less vibration than some other available engines.

Passenger Cabin

In this example, the passenger cabin may have a lightweight frame madeof composite, aluminum, or other suitable material with one stationaryfront wraparound transparent canopy 127 which serves as the windshield,and two pivotally hinged gull wing style doors 126 which are wraparounddoor frames with transparent window material encompassing most of thesurface to serve as the side windows and skylights on each side of thefuselage 100. The doors 126 may also be made of composite, aluminum, orother suitable material. To clarify, these doors 126, when closed, mayserve as skylights on the top and windows on the side. The pilot andfront passenger side of the cabin may have transparent material of ovalor other suitable shape in the floorboard which may provide for downwardviewing and may also provide an emergency escape hatch. The side door126 may pivot wide open to allow for loading/unloading of large loads;e.g., an emergency stretcher or large cargo. It may open large enough toaccommodate the ingress and egress of both the front and rearpassengers. Some embodiments of the present invention may have afour-seat cabin, but other embodiments may include fewer or more thanfour seats, and still other embodiments may be utilized as an unmannedaerial vehicle (UAV) with no seats.

Forward Section of the Aircraft

The headlights/landing lights encasement 101 may have a streamlinedtransparent protective covering located on the nose of the fuselage 100and one front air intake 102 may be located on each side of the nose ofthe fuselage 100. A canard wing 123 may be attached to the frontfuselage 100, with a ducted fan 106 attached to each end of the canardwing by a duct rotation actuator 124. Elevators 116 on the trailing edgeof the canard wing may facilitate in controlling the pitch of theaircraft.

Each of the ducted fans 106 may house a front blade actuator assembly107 which controls the pitch angle of a front row of blades 108 and arear blade actuator assembly 210 which controls the pitch angle of arear row of counter rotating blades 109 (hidden in FIG. 1; see FIGS. 2a, 2 b, 3 a, 3 b). A duct air deflector 110 may be located on the rearof each ducted fan 106. Each of the four ducted fans 106 on the aircraftmay contain the same front and rear blade assemblies and configuration,and each may or may not have a duct air deflector 110 on the rear of theducted fan 110. Alternatively, the ducted fans 106 may not all be of thesame design. For example, in some embodiments, the forward ducted fans106 may be of one design, and the rear ducted fans 106 may be of adifferent design. The air deflector 110 may facilitate control of thetransition from forward flight to hover and back to forward flight orfrom hover to forward flight and back to hover, and control of thesideways and counter rotating motion when in hover.

One front tire 103 may be located on the front bottom of each side ofthe fuselage and may be attached to a fixed front landing gear spar 105and may be partially covered by a streamlined fairing 104 which iswrapped around each tire 103. Alternatively, the tires 103 andassociated landing gear may be retractable into the fuselage 100 or thecanard wing 123. The spars 105 may be fixed, and the tires 103 may bepivoting to provide a tight turning radius. A first avionics bay 128 forstoring the aircraft's computer, gyroscopic equipment, etc. may belocated inside the nose cone. This avionics bay 128 may house the flightcomputers and gyroscopes which handle guidance, navigation and control;for example, it may serve as a data bus which takes the flightinstrumentation, weather and additional data, along with pilot input, tocontrol flight. A second bay may be located in the back (not shown) forredundancy.

Center of the Aircraft

The main wing 113 may be attached to the bottom of the fuselage 100below the passenger cabin doors 126. Alternatively, the main wing 113may be attached to the top of the fuselage 100 or to some intermediateportion of the fuselage 100. A speed brake 111 may be located toward thecenter of the wing 113 on each side of the fuselage to enable theaircraft to slow while in forward flight. The wing 113 may includewinglets 114 to help reduce drag and thereby increase speed and lift;ailerons 115 to help control roll while in forward flight; and flaps 112to help reduce landing speed, move into transitional speed whileswitching from horizontal to vertical and/or back to horizontal flight,and decrease the surface area of the wing thus resulting in less drag onvertical take-off. In some embodiments, other control surfaces may beemployed in combination with or in lieu of speed brakes 111, ailerons115, and flaps 112.

Rear Section of the Aircraft

One rear tire (not shown in FIG. 1) may be attached to a fixed orretractable rear landing gear spar 117 on each side of the fuselage 100toward the aft section of the aircraft. Each of these rear tires may befixed and covered by a streamlined fairing 104 or retractable into theaft portion of the fuselage 100 and may be equipped with brakes.

A ducted fan 106 may be located on each side of the fuselage 100 withthe attachment point located behind the rear passenger cabin/canopy 126.

The rear engine 202 may be mounted slightly higher than the front engine201 to provide room for air intake cooling which may be accomplishedthrough an air intake scoop 118 located behind the passengercabin/canopy 126 and on each side of the fuselage 100.

One fixed vertical stabilizer 120 may be attached on each side and atthe end of the fuselage 100 to minimize or eliminate the yaw/rolloscillations and to reduce the drag off the aft end of the lifting bodyfuselage 100. A rudder assembly 119 attached to the rear of eachvertical stabilizer 120 may help provide yaw control. Atop the verticalstabilizers 120, a horizontal stabilizer 122 may be attached, with arear elevator 121 located on the trailing edge of the horizontalstabilizer 122 for pitch control.

An emergency parachute with deployment rocket launchers may be stored ina storage location compartment 125 in the rear fuselage 100, just behindthe passenger cabin/canopy 126 and above the rear engine 202. Theparachute cables may be attached to the aircraft at four attachmentpoints 129 (three not shown). Two of these attachment points 129 may belocated on each side of the aircraft, with two fore and two aft. Thefront parachute cable on each side may be routed from the attachmentpoint 129 on the front of the aircraft, up the side of the fuselage 100between the front canopy 127 and rear canopy 126, across the top of thefuselage 100 between the left and right hinged gull wing doors 126, andback to the parachute storage compartment 125. The rear attachmentpoints 129 may be located behind and above the air intake scoop 118 oneach side of the aircraft. The rear parachute cable on each side may berouted up the side of the aircraft from the attachment point 129 to thestorage compartment 125. All the parachute cable routings may beconcealed in a recessed channel under a non-protruding breakawaycovering (not shown) which is aerodynamically flush with the fuselage100.

As shown in FIG. 2 a, two double-ended, direct driveshaft engines 201,202 may be mounted longitudinally in-line with one another in thefuselage 100, with one fore and one aft. Engines 201 and 202 may beoriented “sideways” with respect to the fuselage 100 such that the axisof rotation of the driveshaft 204 and 219, respectively, of each engineis oriented transverse to the longitudinal axis of the fuselage. A firstengine 201 may be placed sideways in the front portion of and withrespect to the fuselage 100, and a second engine 202 may be placedsideways in the rear portion of and with respect to the fuselage 100.Each engine 201, 202 may have a double-ended driveshaft 204 or 219,respectively, which powers a pair of ducted fans 106R and 106L forward,and 706R and 706L aft. One ducted fan 106R, 106L may be mounted on eachend of the front canard wing 123, and one ducted fan 706R, 706L may bemounted on each side of the fuselage 100 behind the passengercabin/canopy 126.

In general, this embodiment of the current invention includes a firstpower generation device or engine 201 forward in the fuselage, which isused to power a first driveshaft that serves a ducted fan or propelleron the right canard wing and to power a second driveshaft that servesanother ducted fan or propeller on the left canard wing. In someembodiments, the first power generation device may be a single engine,and the first driveshaft and the second driveshaft may be a singlecontinuous driveshaft 226 that goes through the engine and protrudes outeach end of the engine. In other embodiments described below, the firstpower generation device may be two or more engines in alignment, and thefirst and second driveshafts may be a single continuous driveshaft ormay be separate distinct driveshafts, which may be coupled together toact as a single driveshaft. The same is true for the rear powergeneration device or engine 202 and its associated driveshaft(s).

Forward Engine

The front engine 201 may be mounted in a sideways position with respectto the fuselage 100 between the nose of the aircraft and the frontsection of the cabin/canopy 127. As the double-ended direct driveshaft204 exits each end of the front engine 201, each side of the driveshaft204 runs in an opposite direction and exits the fuselage 100 through atransfer case 203, continues span-wise through the canard wing 123 andduct rotator actuator 124, and connects to an internal duct differential212 in a mid portion of the ducted fans 106L and 106R. The portion ofthe driveshaft 204 that exits the left end of the engine 201 runs to theleft to power the left front ducted fan 106L; the section of thedriveshaft 204 that exits the right end of the engine 201 runs to theright to power the right front ducted fan 106R.

Rear Engine

The rear engine 202 may be mounted in a sideways position with respectto the fuselage 100 behind the passenger cabin/canopy 126. Rear engine202 may be located in-line with the front engine 201 and may be slightlyelevated above the center line of the fuselage 100. Two air intakescoops 118, with one mounted on each side of the fuselage in front ofthe rear engine 202, may provide for air cooling of the rear engine 202.The rear direct driveshaft 219 may be shorter than the front driveshaft204 because the rear ducted fans 706L and 706R may be mounted on eachside of the fuselage 100 just behind the passenger cabin/canopy 126.Similar to the front engine 201, the double-ended direct driveshaft 219exits each end of the rear engine 202, and each side of the driveshaft219 runs in an opposite direction and exits the fuselage 100 through atransfer case 218, continues through a duct rotator actuator 124, andconnects to an internal duct differential 212 in a mid portion of theducted fans 706L and 706R.

In this embodiment, the front transfer case 203 and the rear transfercase 218 may be connected by a transfer case supplemental driveshaft 217which runs just inside of each side of the fuselage 100 between thetransfer cases 203 and 218. These supplemental driveshafts 217 are notnormally engaged; however, should one engine lose power (sometimesreferred to herein as a “dead,” “lost,” or “non-working” engine), acomputer or other controller may engage the supplemental driveshafts 217in the transfer cases 203, 218 thereby bypassing the non-working engine.Through the transfer cases 203, 218 and supplemental driveshafts 217,the working engine may provide power to operate the pair of ducted fans106R and 106L, or 706R and 706L, as the case may be, of the non-workingengine and thus keep the aircraft in a stable position.

The mechanics inside each of the ducted fans 106R and 106L may beidentical except for the entry of the driveshaft 204 through the ductrotator actuator 124 into the duct. The front 204 and rear 219driveshafts extending from the right sides of the engines 201, 202 enterthe right front and right rear ducted fans 106R and 706R from the left;and the front 204 and rear 219 driveshafts running from the left sidesof the engines 201, 202 enter the left front and left rear ducted fans106L and 706L from the right.

In each of the four ducted fans 106, a differential casing 213 may housethe differential 212 and two differential output driveshafts 225. Thedifferential 212 may turn the two differential output driveshafts 225 ina counter rotating motion with one shaft powering a row of variablepitch blades 108 at a front low pressure air intake opening 206 and onepowering another row of variable pitch blades 109 at a rear air outputexpansion chamber 216 of each ducted fan 106. These blades 108, 109 mayturn in a counter rotating motion with two computer controlled actuatorassemblies—one front 107 and one rear 210—determining the pitch of theblades. As the actuator assembly 107, 210 increases the pitch of theblades 108, 109 in each of the ducted fans 106, air flow is increasedthrough the front air intake 206, is compressed in the high pressurechamber 306, and is exhausted by the rear row of blades 109 through theexpansion chamber 216. This creates the thrust for takeoff in eithervertical or forward flight. FIGS. 3 a, 3 b, and 3 c show enlargedillustrations of the ducted fans 106, and FIGS. 4 a, 4 b, and 4 cillustrate various rotational positions of the ducted fans 106 and howthey affect take-off, flight, hover, and braking.

As shown in FIGS. 3 a, 3 b and 3 c, each of the ducted fans 106 is aducted tilt rotor, which may be composed of a lightweight composite,aluminum, or other suitable material. The rows of blades 108, 109 insidethe ducts may be driven by a direct driveshaft 315 from a double-endedengine 201, 202 which is mounted sideways with respect to the aircraftfuselage 100 as described above. Referring also to FIGS. 2 a and 2 b,driveshaft 315 may be located in either the front of the aircraft asshown by element 204 or in the rear of the aircraft as shown by element219. The driveshaft 315 may enter each ducted fan 106 from the side andconnect inside the differential casing 213 with the differential 212 ina mid portion of the ducted fan 106. Extending from the differential212, a forward output shaft 307 and a rear output shaft 310 mayrespectively drive a forward row of fan blades 108 in a front portion ofeach ducted fan 106 and a rear row of fan blades 109 in a rear portionof each ducted fan 106. The fan blades 108, 109 may turn in a counterrotating motion which may create more thrust and reduce the overalldiameter of the ducted fans 106, thereby providing sufficient groundclearance for conventional aircraft take-off and landing mode as well asVTOL capability.

FIG. 3 a and FIG. 3 b illustrate the aerodynamic shape of the front ofeach of the ducted fans 106, with the bottom of each ducted fan 106protruding forward as a lower front induction scoop 301 and with the topof each ducted fan 106 sloping down from an upper front induction scoop302 to the lower front induction scoop 301, thereby creating more liftand less drag. This lifting air intake duct design may create a lowpressure area 206 in the bottom front of the duct which in turn createslift. This design may reduce or eliminate the need for more wing areaand in turn may reduce the weight of the aircraft.

FIG. 3 a also shows a high pressure inner compression chamber 306located between the two rows of rotating fan blades—front 108 and rear109—in each ducted fan 106. The front blade actuator 107 changes thepitch of the front blades 108. By increasing the pitch of the front rowof blades 108, air is pulled in and compressed in the high pressureinner compression chamber 306. The rear blade actuator 210 changes thepitch of the rear row of blades 109. The rear blades 109 pull the airfrom the high pressure inner compression chamber 306 and exhaust the airthrough the low pressure expansion chamber 216 thereby creating forwardthrust.

The blades in each row may have variable pitch controlled by fly-by-wirecomputers which relay information to the front blade actuator 107 and tothe rear blade actuator 210 to adjust the angle of the blades. Gyroslocated in the avionics bays may send a computer signal to the bladeactuators 107, 210 to help control the stability of the aircraft inhover. The blades may be capable of self feathering and lining up in anidentical configuration behind one another within each ducted fan 106 tohelp reduce drag and to increase air flow through the ducts, should anengine be lost or shut down. This feathering feature may extend therange which can be flown with one engine.

Each ducted fan 106 may also have a rear air deflector 110 mountedvertically, horizontally, or in another desired configuration on therear of the ducted fan 106 when positioned for forward flight or otherflight condition. This deflector 110 may be controlled by a fly-by-wireactuator 300 and may divert air to the left, right, or other desireddirection to help stabilize the aircraft when it transitions from flightto hover or undergoes another desired maneuver. While in hover mode, thedeflector 110 may divert the air to provide the ducted fans 106 with thecapability of moving the aircraft sideways. Additionally, the airdeflector 110 on the rear of the front ducted fans 106 may move one waywhile the air deflector 110 on the back of the rear ducted fans 106 maydivert in the opposite direction or another desired direction, thusgiving the aircraft counter-rotation capabilities.

FIGS. 4 a, 4 b and 4 c show the position of the ducted fans 106 inforward flight, hover, and reverse, respectively.

FIG. 4 a shows the position of the ducted fans 106 for forward flightand for take-off in conventional fixed wing mode.

FIG. 4 b illustrates the position of the ducted fans 106 in hover andfor vertical take-off. As the aircraft is lifting vertically as shown inFIG. 4 b, forward movement may be accomplished by a computer controlledduct rotator actuator 124 rotating the ducted fans 106 forward towardthe position shown in FIG. 4 a to create forward movement until suchspeed is reached that sufficient airflow over the lifting surfacescreates lift, and the aircraft transitions from vertical to horizontalflight.

While in forward flight as shown in FIG. 4 a, the ducted fans 106 mayremain in aerodynamic alignment with the fuselage 100 as with aconventional fixed wing aircraft. When transitioning from horizontalflight to vertical flight, the duct actuators 124 may be rotated upwardto slow the forward motion as shown in FIG. 4 b. This decreases the airspeed thus reducing the airflow over the lifting surfaces, and as theducted fan 106 is rotated back to the upward position, it may increasethe vertical thrust of the variable pitch blades. The actuators 124 mayturn the ducted fans 106 past vertical as shown in FIG. 4 c to slow theaircraft to a complete stop of forward motion. The tilted duct rotatoractuator 124 may also control forward and reverse motion in hover bymoving the ducts 106 forward or backward, respectively.

Description of Alternative Embodiment—UAV

In this embodiment, the aircraft may be adapted to perform as anunmanned aerial vehicle or UAV. This embodiment may include the sidewaysengine placement and in-line alignment and the fans encased in ducts asdescribed for previous examples above. Most of the configuration of theaforementioned embodiment may remain intact, but some differences may beprovided to help reduce the radar signature and to help provide for thecarrying of weapons, large payloads, surveillance equipment, or thelike. The aircraft and the engine may be scaled up or scaled down toaccommodate different weight and/or mission objectives.

The UAV embodiment may include the same tail configuration of theprevious examples, that is, the vertical stabilizers with the horizontaltail atop them, or as pictured in FIG. 5, it may utilize a V-tailassembly 501 and may include horizontal stabilizers 502 attached to thesides of and/or to the rear of the ducts (not shown). This V-tailconfiguration is similar to that of the Raptor F-22.

Other differences may include a retractable landing gear instead of afixed landing gear, foldable wings or changeable wings for high altitudeand other applications, a large compartment in place of a passengercabin, and a camera location in the nose cone for surveillance. Thecabin canopy may be manufactured of an opaque material rather than atransparent material and may become more aerodynamically streamlined byincorporating a lower profile. Bomb bay doors which open at the bottomof the aircraft for deployment of weapons, emergency food supplies, orthe like may improve stealth capabilities because those items may behidden and encased in the fuselage rather than placed on the wings.

The UAV embodiment may be used for military and reconnaissanceoperations for close in support. The UAV embodiment may also be used asan emergency vehicle to pick up wounded or stranded people in adangerous location. The bolt-on or foldable wings may allow it to betrailered to a nearby or safe location before being sent on a mission.Thinner and longer wing extensions may accommodate higher altitudes andlonger loitering. The ability of the aircraft to fly with one engineshut down and to take-off and land in close proximity to a target areamay increase the distance the aircraft can fly on its designated fuelallowance. The engine may have the ability to alternate piston firingswhich also may increase fuel economy while keeping the aircraft aloftusing very little horsepower.

Since the fan blades may be encased in ducts, and since ducted fans arequieter than propellers or jet engines, less radar signature may beproduced. Also, since the engines may be mounted in the fuselage, lessinfrared signature may be produced. Stealth may therefore be muchimproved.

In some embodiments, most or all of the cabin area between the twoengines may be used for storage of weapons, cargo and supplies, and/orsurveillance equipment. VTOL capabilities may allow the aircraft to getcloser to a target or to get into tight areas as for a rescue. Theability to take off and land in conventional mode may provide for morecarrying capacity because the wings may be used for lift so the aircraftmay carry more fuel and weight. Once the fuel has burned off on a longflight, a vertical landing is possible.

The V-tail configuration 501 could also be utilized on the passengerembodiments to improve the speed of the aircraft.

Description of Alternative Embodiment—Sport Plane

FIG. 6 shows an alternative embodiment of this invention as a VTOL sportplane. This embodiment may be comprised of an elongated aerodynamicfuselage with one double-ended driveshaft engine mounted sideways withrespect to the fuselage and with a rotatable ducted fan 106 on each endof a main fixed wing 605 for a total of two ducted fans. The wing 605may be level, dihedral, or anhedral. A passenger compartment/cabin 600in the front portion of the fuselage may accommodate one or two people,and the engine may be located in the fuselage just behind cabin 600 andin line with the wing 605. An emergency parachute compartment may belocated behind the passenger cabin 600 and just above the engine. Theaircraft may have a fixed or retractable tricycle landing gear with oneattached to the front 601 of the fuselage and two 602—one left and oneright—attached to the bottom of the fuselage behind and below thepassenger compartment 600.

In this embodiment, the engine, driveshaft, transfer case, duct rotatoractuator, and ducted fans 106 may be provided for wing 605 in likemanner as described above for canard wing 123 (see FIGS. 1, 2 a, 2 b).The double-ended driveshaft from each end of the engine may exit thefuselage through a transfer case, bearing, or other suitable support,run inside the main fixed wing 605, continue through a duct rotatoractuator, and continue through a side of the ducted fan 106 and into amid portion of the ducted fan 106 where it connects to a differential.As the driveshaft exits the right end of the engine, it runs through theright side of the wing and enters the right ducted fan 106 through theleft side; and as the driveshaft exits the left end of the engine, itruns through the left side of the wing and enters the left ducted fan106 through the right side. Inside each ducted fan 106, the differentialmay have two output shafts with each one turning one row of blades.Therefore, the two output shafts may respectively turn two rows ofcounter rotating blades in each ducted fan 106.

Two air deflectors—one vertical 110 and one horizontal (not shown inFIG. 6)—may be attached to the rear of each ducted fan 106. Thesedeflectors may employ a DSS (Duct Stabilization System) and may usesplitting capabilities to control the output thrust for increasedstability. The horizontal air deflector may move the aircraft forwardand backward, and may provide counter rotation of the aircraft in hover.The vertical air deflector may move the aircraft sideways in hover. Inconventional airplane mode, the horizontal air deflector may control theroll.

The rear fuselage of the aircraft may be long and streamlined with acruciform shaped tail comprised of one left 604 and one right (notshown) horizontal surface and one top 603 and one bottom verticalsurface (not shown) controlling pitch and yaw, respectively, while theaircraft is in conventional airplane mode.

Description of Further Alternative Embodiments Multiple Engines PlacedEnd to End

In this embodiment, as shown in FIG. 2 b, two or more engines may beprovided fore, and two or more engines may be provided aft. Each set ofengines may be placed end to end and sideways with respect to thefuselage. A common driveshaft or coupled driveshafts which act as onedriveshaft 226 may run through the multiple engine blocks, with theshaft output on the outside ends of the outside engines running a pairof propellers or ducted fan blades. In this example, a transfer case maynot be necessary for a backup for a dead engine, although a transfercase and supplemental drive shaft may be provided for furtherredundancy. The dead engine shaft may be driven by the running engineand/or engines with the dead engine freewheeling. The propellers orducted fan blades may keep turning but at reduced power.

In some embodiments, freewheeling may be accomplished by couplingmultiple engines (two or more) in-line with a continuous or coupleddriveshaft and/or camshaft to effectively create a single power sourceand to provide for the freewheeling of one or more engines or for all ofthe engines, further described as follows. The freewheeling system maybe formed by placing two or more engines (power sources) end to end andwith each combined engine having a common driveshaft (which may be oneintegral, continuous shaft or multiple shafts coupled together) enablingthe other engine or engines to freewheel. The sizes, horsepower, andtypes of power sources for such embodiments may be identical or varied.Output shafts for freewheeling can be utilized from each end, or fromonly one end, or from the middle of the coupled or continuous shafts.Coupling of multiple power sources may provide for the capability offreewheeling of one or more power sources while one or more other powersources are providing power to the other end of the freewheelingengine(s). It may also provide for all of the power sources to runtogether or for all power sources to freewheel together. If one powersource fails, the other power source(s) will continue to turn thedriveshaft, thus providing redundancy and enhanced safety.

In some embodiments, each of the power sources may provide a differentpower level for the coupled unit; e.g., if three power sources arecoupled, one power source could be at idle, one could be at mediumpower, and one could be at full power, or alternatively all the powersources could be working at full power. More generally, each powersource may be utilized at any selected power level. Significant fuelsavings may result from regulating the power to only what is necessaryat a given flight condition. In addition, any combination of the powersources could be selected to power or freewheel, and the power sourcesmay be alternately selected so that the hours on each of the powersources may be maintained at a similar level if needed.

In some embodiments, coupling of the power sources with the resultantfreewheeling capability may eliminate the need between units forclutches, transmissions, torque converters and/or differentials. Thismay simplify manufacturing and operations, thereby reducing costs ofoperation and maintenance and increasing safety. Alternatively, variousfreewheeling devices may be interposed between a power source and thedriveshaft if needed.

In some embodiments, coupling two or more different types of powersources—such as one heat source (e.g., internal combustion or jetengine) and one electrical source, for example—may provide for variouscapabilities. The heat source may be utilized to turn an electric sourceinto a generator, thus letting the heat source charge batteries, forexample. The heat source may provide power while freewheeling theelectric source. Alternatively, the electric source may provide power byfreewheeling the heat source, or both the heat source and the electricsource may be used together to provide hybrid power. As anotheralternative, both sources may be freewheeled and used in a regeneratingmode to turn the electric source into a generator and provide brakingand electrical current to charge batteries.

In some embodiments, the multi-source unit being used to power agenerator(s) may continue to generate power—even with the loss of anengine—because the other engine(s) may accelerate to compensate for thedead engine, thus eliminating or minimizing loss of power.

In some embodiments, some of the power units for which this freewheelingconcept may work best may be power sources which produce very littlefriction when the power source is freewheeling and the continuous orcoupled driveshaft(s) are in-line, thus using internaldriveshafts/crankshafts/cam shafts as the drive line. The internalmechanical parts of the engine may be used as the continuous drive linewhich turns the output shaft with power from the other power source(s).

In some conventional aircraft applications, coupling the engines forfreewheeling may make it possible for one drive shaft from one end ofthe coupled power units to turn one propeller unit. This configurationmay eliminate the need for other drive shafts when a back-up engine isneeded, thereby reducing drag while still providing the “back-up” safetyelement of conventional twin engines or multi-engines.

In some embodiments, the freewheeling system may also work insidenacelles; e.g., by placing propellers on one end of multiple engines,between the engines, or at each end of the engines. This configurationmay also be used to retrofit an existing aircraft by placing a propellerat one end of combined engines.

In some embodiments, this coupled and freewheeling power generating unitmay provide both power and back-up power from each end or from one endof the coupled power unit and may be used in a VTOL aircraft to providefor powering the aircraft. It may also be used to improve the poweringof existing VTOL aircraft currently in design, production, and/or use.Currently, many of these aircraft have propellers and blades at the endof the engines or in the ducts with their power units creating safetyissues if one engine fails. In some embodiments, coupling enginestogether may allow the use of smaller engines thereby reducing the costof manufacturing, especially for electric motors, since smaller enginesgenerally cost less to manufacture.

Some examples of reduced friction power units that may be used forcoupling may include engines such as the Perlex™, Axial Vector™,Sinusoidal Cam™, Dyna-Cam™, Radmax™, Rand-Cam™, Wankel™, and anycylindrical rotor, rotor, rotary, mill, vane, turbine, jet, electric andany other reduced friction power units capable of using its internaldrive shafts in freewheeling applications as described herein.Alternatively, some conventional engines may be used if the amount offriction produced in them may be reduced.

In some embodiments, freewheeling may be provided in connection withactuators and servo motors. As shown in FIGS. 3A and 3B, a common shaft307, 310 may be provided between the two actuators 107 and 210, whichmay be connected to allow redundancy for the control of the variablepitch blades 108 and 109 by allowing the freewheeling of a failedactuator. In some embodiments, common shaft 307, 310 may be hollow witha rod traversing through the middle, with the outer portion of the shaftserving to power blades 108, 109 and the inner rod serving to connectactuators 107, 210, such that if one of the actuators 107, 210 losespower the other of the actuators 107, 210 may continue to control thepitch of the first and second rows of blades 108, 109. This type ofapplication may also be applied to many different scenarios for backupsystems. For example, actuators and servo motors may be stacked (i.e.,operably engaged with a common driveshaft) like the multiple enginesdescribed above, or separated and equipped with separate power sourcesin the event one power source fails. Such actuators and servo motors maybe connected by a common shaft thus allowing freewheeling of a deadactuator or servo motor.

Some embodiments may have two engines fore and two engines aft with eachpair of engines comprising a first engine fore and a next engine aft.Each pair of engines may be placed end to end and in-line and sidewayswith respect to the fuselage. Each engine may be controlled separatelywith the driveshaft from the right engine turning the propellers orducted fan blades on the right side of the aircraft and with thedriveshaft from the left engine turning the propellers or ducted fanblades on the left side of the aircraft. Transfer cases may be used inthis example to pick up the power from the other engines.

Emergency Rescue Vehicle

This embodiment may use modifications to provide for an emergency rescuevehicle. The changes comprise shortened wings, a stubby nose, a frontcanopy that would fold or retract backwards, and a platform additionwhich would facilitate emergency escapes. The emergency vehicle couldnose in to a building, cliff, or the like to provide an escape route forpeople trapped in, for example, a burning building. Ducted fans—asopposed to propellers—may permit the aircraft to get next to structuresor into tight areas. The stubby nose and retractable canopy may allowaccess to the aircraft. An extendible/retractable ramp in the nosesection may provide a stable emergency escape route.

Various embodiments of the aircraft described herein may utilize one ormore of various types of engines, including Axial Vector, Dyna-Cam typeengines, internal combustion, radial, piston, reciprocating, rotary,rotor, StarRotor, vane, mill, electric, hybrid, diesel, or similar typeengines, alone or in combination, mounted in-line and sideways withrespect to the fuselage. Hybrid engines may include one or more of eachof a plurality of engine types. For example, a hybrid engine may includea diesel portion and an electric portion.

In some embodiments, an electric engine may have a first mode in whichthe electric engine drives the driveshaft and a second mode in which theelectric engine serves as a generator driven by the driveshaft andcharges a battery electrically connected to the electric engine. Forexample, the electric engine may operate in the first mode duringtake-off and the electric engine may operate in the second mode aftertake-off.

In some embodiments, the front ducted fans may be mounted at the end ofthe canard wing, and the rear ducted fans may be mounted on each side ofthe fuselage just behind the passenger canopy. However, in otherembodiments, the ducted fans may be mounted on each side of the frontpart of the fuselage, on each end of the main wing, and/or on the tail,depending upon the configuration of the aircraft.

In some embodiments, propellers may be utilized to handle larger loadswith less horsepower, and the engines may be mounted in a higherposition on the fuselage to provide clearance for the propellers. Thisconfiguration may accommodate from six to ten passengers or a largepayload, for example.

Any or all of the embodiments may utilize an emergency parachute system.The aircraft may be equipped with a parafoil type parachute and one ormore deployment rockets for emergencies. The deployment rockets may besolid fuel, liquid fuel, gaseous fuel, or a combination thereof. Theparachute may primarily be used while in hover mode or at slow speeds,but may be used in other flight conditions if necessary or desired. Theparachute and rockets may be mounted in the top of the rear portion ofthe fuselage behind the rear cabin, with one rocket on each side, forexample. A cable system may be imbedded in the fuselage with a breakawaycovering as described above. The supporting cables may be attached tothe airframe at four attachment points as described above—two in thefront fuselage near the outside end of the front engine and two in therear fuselage near the outside end of the rear engine. The risers fromthe parachute may be attached to the supporting cables.

The emergency parachute may be deployed by the pilot via an emergencyhand lever if the aircraft is in forward flight, or it may beautomatically deployed by a computer if an engine loses power or theaircraft becomes unstable in hover or other flight condition. Theparachute system may deploy the rockets, shooting them out at an angleand pulling the ends of the parafoil parachute in opposite directions,thereby moving the parachute away from the aircraft appendages andstretching the canopy to the full length of the parachute.

Airbag technology with small elongated tubes embedded in the parachutecanopy cords and the outer edges of the parachute system may be utilizedto immediately expand the parachute into the ultimate shape of a fullydeployed parachute. The canopy may then be ready to receive the air, andthis may result in the aircraft suffering a very slight loss of altitudefrom the time the parachute deploys until it is filled with air.

If the aircraft is moving in forward flight, computer controlled airsensors may determine if a need exists to apply or delay deployment ofthe airbag expander of the air canopy. This may minimize the shock fromthe forward air speed. When the parachute is opened, it may be steeredvia controls inside the aircraft. The parafoil parachute may give theaircraft a forward motion to help steer the aircraft to a safe area fora landing while descending under the parachute. If one engine is stilloperating, the parachute may act as a parasail to help keep the aircraftaloft while the pilot leaves a dangerous area and searches for a safelanding site.

Since the emergency parachute may be computer controlled in hover orother flight condition, it is possible the emergency backup transfercase and supplemental driveshafts may be bypassed or eliminated fromcertain embodiments thereby streamlining and simplifying the design ofthe output shafts from the engine to each differential. This maysignificantly reduce the weight of the aircraft.

The embodiments described above are some examples of the currentinvention. Various modifications, applications, substitutions, andchanges of the current invention will be apparent to those skilled inthe art. Further, it is contemplated that features disclosed inconnection with any one embodiment, system, or method may be used inconnection with any other embodiment, system, or method. The scope ofthe invention is defined by the claims, and considering the doctrine ofequivalents, and is not limited to the specific examples describedherein.

1-14. (canceled)
 15. An aircraft comprising: a fuselage having alongitudinal axis; a first engine disposed in said fuselage; a secondengine disposed in said fuselage; said first and second engines beingoperably connected to a common driveshaft traversing through said firstand second engines and having an axis of rotation oriented transverse tosaid longitudinal axis of said fuselage; a first propeller operablyconnected to said common driveshaft; and a second propeller operablyconnected to said common driveshaft; wherein said first and secondengines are configured for freewheeling such that if one of said firstand second engines loses power the other of said first and secondengines continues to power said first and second propellers.
 16. Theaircraft of claim 15 wherein each of said first and second propellerscomprises a ducted fan.
 17. The aircraft of claim 16 wherein said ductedfans are tiltable to facilitate VTOL and forward flight.
 18. Theaircraft of claim 17 wherein each of said ducted fans is mounted to awing extending from said fuselage.
 19. The aircraft of claim 16 whereineach of said ducted fans comprises counter-rotating blades.
 20. Theaircraft of claim 15 wherein each of said first and second engines isoperable at a selected power level.
 21. The aircraft of claim 20 whereinsaid first and second engines are selectable such that the hours on eachof said first and second engines are maintainable at a similar level.22. The aircraft of claim 15 further comprising a nose section having anextendable and retractable ramp.
 23. The aircraft of claim 15 furthercomprising a retractable canopy.
 24. The aircraft of claim 15 furthercomprising a parachute attached to said fuselage.
 25. The aircraft ofclaim 24 wherein said parachute is mounted in a rear portion of saidfuselage.
 26. The aircraft of claim 24 further comprising one or morerockets configured for deploying said parachute.
 27. The aircraft ofclaim 24 further comprising cables configured for attaching saidparachute to said fuselage, wherein said cables are concealed in arecessed channel under a non-protruding breakaway covering which isaerodynamically flush with said fuselage.
 28. The aircraft of claim 27wherein said cables are attached to said fuselage at four attachmentpoints.
 29. The aircraft of claim 24 wherein said parachute isautomatically deployable by a computer if said aircraft becomesunstable.
 30. The aircraft of claim 24 wherein said parachute ismanually deployable by a lever.
 31. The aircraft of claim 24 furthercomprising an airbag expander configured for expanding said parachuteinto a fully deployed condition.
 32. The aircraft of claim 31 whereinsaid airbag expander comprises elongated tubes embedded in canopy cordsand outer edges of said parachute.
 33. The aircraft of claim 31 furthercomprising computer controlled air sensors configured for determiningwhether to apply or delay deployment of said airbag expander.
 34. Theaircraft of claim 24 wherein said parachute is steerable via controlsinside said aircraft.